Automatic clamping and locking apparatus

ABSTRACT

An automatic clamping arrangement for clamping a sleeve and the like onto a shaft and the like includes at least two levers pivotally mounted on said shaft and disposed in chamber means therein. The levers are disposed for generally opposed movement toward and away from the sleeve when the latter is mounted upon the shaft. Biasing means are coupled to each of the levers for angularly displacing the levers about their pivot mountings such that a portion of each of the levers is advanced toward an adjacent surface of the sleeve. A clamping projection on each of the lever portions is disposed for bearing contact with said sleeve surfaces upon pivoting of the levers by the biasing means. The chamber means communicate through recess means opening onto a surface of the shaft for insertion of a tool generally between opposed second portions of the levers to pivot the levers in an opposite direction against the action of the biasing means to withdraw the clamping projections from the sleeve surfaces.

United States Patent 1 Lemper 1 AUTOMATIC CLAMPING AND LOCKING APPARATUS [75] Inventor: Herbert Lemper, Bethel Park, Pa.

[73] Assignee: Mesta Machine Company,

Pittsburgh, Pa.

1221 Filed: Feb. 22, 1972 211 Appl. No.: 228,121

Primary Examiner-Milton S. Mehr Attorney-Donn J. Smith June 19, 1973 [57] ABSTRACT An automatic clamping arrangement for clamping a sleeve and the like onto a shaft and the like includes at least two levers pivotally mounted on said shaft and disposed in chamber means therein. The levers are disposed for generally opposed movement toward and away from the sleeve when the latter is mounted upon the shaft. Biasing means are coupled to each of the levers for angularly displacing the levers about their pivot mountings such that a portion of each of the levers is advanced toward an adjacent surface of the sleeve. A clamping projection on each of the lever portions is disposed for bearing contact with said sleeve surfaces upon pivoting of the levers by the biasing means. The chamber means communicate through recess means opening onto a surface of the shaft for insertion of a tool generally between opposed second portions of the levers to pivot the levers in an opposite direction against the action of the biasing means to withdraw the clamping projections from the sleeve surfaces.

15 Claims, 5 Drawing Figures AUTOMATIC CLAMPING AND LOCKING APPARATUS Certain features of the present application are related to co-assigned US. Pat. No. 3,559,441 coinvented by myself and William E. Ennis and entitled FRAMELESS ROLL CHANGING DEVICE FOR ROLL LEVELER STRAIGHTENER AND THE LIKE; and to my copending coassigned application entitled ROLL LEVELER STRAIGHTENER AND THE LIKE, filed concurrently herewith, Ser. No. 227,874.

The present invention relates to automatic clamping and locking apparatus and more particularly to apparatus of the character described for automatically locking and unlocking rolls or sleeves on cantilevered shafts, such as on the shafts of a roller straightener.

As sometimes used herein the terms straightener or roller straightener" is inclusive also of similar leveler devices and equivalent apparatus.

Structural mill straighteners or levelers are employed throughout the steel and related industries for straightening various structural shapes such as beams, angles and rails. Such devices employ usually a number of rolls, with seven or more such rolls being common. In practice, the rolls of the leveler or straightener must be changed to accommodate each shape or size of product to be leveled or straightened, Frequent roll changes, are, therefore, required. Depending upon product mix, it is often desirable to change the rolls of the straightener or leveler as frequently as two or three times per shift. However, with the considerable time involved in making such changes, according to the largely manual practices still in use, such frequent roll changes are not practical.

As pointed out in the aforementioned patent the time involved in making such roll changes has been drastically reduced and personnel hazard has been substantially eliminated by the roll changing apparatus described and claimed therein. In fact, the aforesaid roll changing apparatus has been able to reduce the roll changing operation from a matter of several hours to approximately 30 minutes per roll change. However, of this 30 minutes, only 1 or 2 minutes are required by the roll changing apparatus to make the actual withdrawal of the used rolls and installation of the new rolls. The remaining 28 to 29 minutes are required by operating personnel for manually loosening locking plates, removal of nuts and split rings, and after the new rolls have been put in place, replacing the split rings, nuts and locking plates and performing the necessary tightening operations.

These manual operations cannot of course be performed by the aforementioned roll changing apparatus, as these operations are related directly to conventional manner hardware and procedures for clamping and locking the straightener rolls or sleeves in place.

I overcome these disadvantages of the prior art by providing a unique and unexpected arrangement whereby a roll or sleeve or the like can be quickly and automatically clamped or locked on a cantilevered shaft and whereby in a similar manner the roll or sleeve can be unlocked or unclamped from the shaft. The automatic clamping and locking apparatus of the invention is simple in construction and can be advantageously incorporated with the roll shaft of a leveler or straightener, or other apparatus where space is at a premium. At the same time, the automatic clamping and locking apparatus is capable of self-actuation to develop relatively large clamping or locking forces capable of clamping or locking straightener rolls on their shafts, which rolls may weigh as much as 3,300 pounds and more. Most importantly, my novel clamping and locking apparatus can be actuated without removal of clamping plates, lock nuts, split rings, or other hardware. Likewise, no hardware need] be removed prior to either installation or removal of the roll or sleeve.

The invention also contemplates an unexpected modification of the roll changing apparatus described and claimed in the aforementioned patent. With such modi fication, the roll changing apparatus is surprisingly ca pable of manipulating simultaneously a number of the aforementioned automatic clamping and locking devices such that the roll changing apparatus can with draw the used rolls and install new rolls on a straightener or the like without prior removal or subsequent addition of clamping plates, lock nuts, split rings or other hardware. Thus the time formerly allotted to removal and replacement of the aforementioned hardware, which as noted above amounts to over percent of the total roll changing operation, is completely eliminated.

I accomplish these desirable results by providing an automatic clamping arrangement for clamping a sleeve and the like onto a shaft and the like, said arrangement comprising at least two levers pivotally mounted on said shaft and disposed in chamber means therein, said levers being disposed for generally opposed movement toward and away from said sleeve when the latter is mounted upon said shaft, biasing means coupled to each of said levers for angularly displacing said levers about said pivot mountings such that a portion of each of said levers is advanced toward an adjacent surface of said sleeve, and a clamping projection on each of said lever portions disposed for bearing contact with said sleeve surfaces upon pivoting of said leversby said biasing means, said chamber means communicating through recess means opening onto a surface of said shaft for insertion of a tool generally between opposed second portions of said levers to pivot said levers in an opposite direction against the action of said biasing means to withdraw said clamping projections from said sleeve surfaces.

I also desirably provide a similar automatic clamping arrangement wherein said second lever portions are provided with cam follower means for cooperative engagement with a camming surface of said tool.

I also desirably provide a similar automatic clamping arrangement wherein said biasing means include a compressed spring for each of said levers, said springs being confined respectively between retaining recesses on said levers and on spring retaining members mounted within said chamber means.

I also desirably provide a similar automatic clamping arrangement wherein said chamber means terminate in said shaft outwardly of an adjacent end portion of said sleeve, and said levers each include third portions insertable between said sleeve end portion and adjacent end surfaces of said chamber means upon pivoting of said levers by said biasing means to lock said sleeve on said shaft against stop means thereon disposed adjacent the other end of said sleeve.

1 also desirably provide a similar automatic clamping arrangement wherein said third lever portions include a like number of dogs pivotally mounted on said levers respectively and shaped for bearing insertion between said sleeve end and said chamber end surfaces.

I also desirably provide a similar automatic clamping arrangement wherein sleeve changing apparatus is provided for said sleeve and said shaft, said sleeve is cantilevered on said shaft and-said recess means open onto an end of said shaft, said tool being an elongated stud member secured to said apparatus, said apparatus having at least one sleeve-receiving socket, said stud member being secured to said apparatus and protruding outwardly and centrally from said socket for insertion into said shaft recess and chamber means, and cooperating locking means are formed on said sleeve and on said socket for locking said sleeve to said socket during withdrawal and replacement movements thereof relative to said shaft.

I also desirably provide roll changing apparatus for use with a shaft having a cantilevered roll thereon and clamping mechanism therein for said roll, said clamping mechanism being actuatable by a tool insertable into axial recess means in said shaft, said recess means opening onto an end of said shaft, said changing apparatus having at least one sleeve-receiving socket, said tool being an elongated stud member secured to said changing apparatus and protruding outwardly from the interior of said socket for insertion into said shaft recess means, and cooperating locking means formed on said roll and on said socket for locking said roll to said socket during withdrawal and replacement movements thereof relative to said shaft.

During the foregoing discussion, various objects, features and advantages of the invention have been set forth. These and other objects, features and advantages of the invention together with structural details thereof will be elaborated upon during the forthcoming description of certain presently preferred embodiments of the invention and presently preferred methods of practicing the same.

In the accompanying drawings I have shown certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same, wherein:

FIG. 1 is a longitudinally sectioned view of a sleeve member such as a straightener roll, a portion of its supporting shaft, and one form of my automatic clamping and locking apparatus incorporated in the shaft;

FIG. 2 is a similar view of the apparatus shown in FIG. 1 but illustrating the automatic clamping and locking apparatus in its unclamped and unlocked position, together with means for so manipulating the clamping and locking apparatus. FIG. 2 also shows a modification of my roll or sleeve changing apparatus provided with means for so manipulating a number of the mounting and locking devices of the invention;

FIG. 3 is a front elevational view of the apparatus as shown in FIG. 1;

FIG. 4 is a cross-sectional view of the apparatus as shown in FIG. 1 and taken along reference line IV-IV thereof; and

FIG. 5 is a similar view along reference line VV of FIG. I.

Referring now more particularly to FIGS. 1 and 3-5 of the drawings, an exemplary form of the automatic clamping and locking apparatus 20 is arranged in this embodiment for incorporation into a cantilevered end portion of shaft 22, which is rotatably mounted in bearing housing 24 or on other suitable support. The clamping and locking apparatus 20 is self-energizable for clamping and locking a sleeve or roll 26 upon the cantilevered end portion of the shaft 22. The cantilevered end portion of the shaft 22 can be slightly tapered for receiving the sleeve or roller 26. In addition, the end portion of the shaft 22 is provided with a cylindrical recess 28 extending in this embodiment coaxially of the shaft 22 as shown.

Near the outward end of the shaft 22 the recess 28 is widened into the number of chambers 30 to accommodate the operative components of the automatic clamping and locking device 20. As evident from FIGS. 4 and 5 three such chambers 30 are provided, each of which contains an operating lever 32 described below. However, it is to be understood that a different number of chambers 30 and operating levers 32 can be furnished, as long as two or more such levers 32 are positioned generally in opposition to one another..

An end cap 34 is secured to the outward end of the shaft 22, which protrudes outwardly of the sleeve or roll 26 when the latter is in place, as denoted by reference characters 36. The end cap 34 is secured to the shaft portions or partitions 38 (FIG. 4) remaining between the chambers 30, by a number of cap screws (FIG. 3). It will be observed that the outer periphery of the end cap 34 is about the same diameter as that of the end portion 36 of the shaft 22, or in any event is less than the inner diameter of the sleeve or roll 26. Therefore it is feasible, and it is one of the principal and unexpected features of the invention, that the sleeve or 'roll 26 can be installed and withdrawn over the end cap 34 without removal of the end cap or any other hardware. There is no necessity for removing the end cap 34 throughout the life of the straightener or leveler or other apparatus on which the roll 26 and shaft 22 are utilized, save for maintenance of the automatic clamping and locking arrangement 20.

Each of the aforementioned pivotally mounted levers 32 are mounted on an associated pivot pin 42 extending between adjacent shaft segments or partititions 38, as evident from FIG. 4 of the drawings. The pins 42 are provided with sufficient diameter to withstand the clamping forces applied to the lever or roll 26 in the manner described below.

On the inward end portion of each lever 32, a spring retainer groove 44 is formed for engagement with com pressioned lever spring 46. The other end of the spring 46 is seated in one of the spring retainer members 48 inserted into each of the lever chambers 30, where they are bolted or otherwise secured to the adjacent shaft partitions 38. The spring 46 is thus arranged normally to urge the inward end portions of the levers 32 toward center line 52 of the shaft 22. Also mounted on the inward end portion of each lever 32 is a cam follower 50 whose function is likewise described below.

However, just before the inward end portion or cam follower 50 of each lever reaches the center line 52, under impetus of the associated spring 46, a clamping projection 54 of each lever 32 engages the adjacent inner surface of the sleeve or roll 26. In effect, then, the moment arm of the clamping projection 54 is very short such that further movement of the lever 32 by the spring 46 causes a very large clamping force (arrow P1) to be exerted against the adjacent surface of the sleeve or roll 26. As evident from FIG. 1 the spring retainer members 48 terminate short of the contacting surfaces of the clamping projections 54 and the associated surfaces of the sleeve or roll 26 so as not to interfere with contact therebetween. In the illustrated embodiment, the springs 46 are arranged to apply considerable forces to the inward end portions of the levers 32 such that there can be no failure in the application of the very large clamping forces to the sleeve or roll 26, by the levers 32. The levers 32 and the pins 42 are of sufficiently rugged construction as to withstand the huge clamping forces engendered by pivoting of the le vers 32.

Desirably each projection 54 is shaped and disposed to provide initially an edged contact, by means of its leading edge 53, with the adjacent surface of the sleeve or roll 26. This structural and spatial relationship minimizes friction as the edge 53 is dragged across the adjacent surface 55 of the sleeve 26 until at the fully pivoted position of the levers 32, the outward surfaces 57 of the clamping projections 54 are seated more or less flushly against the sleeve surfaces 55, as shown in FIG.

Adjacent the front end of each lever 32 bifurcate extensions (FIG. 5) 56 are formed by means of an intermediate slot 58 formed in the lever. A locking dog 60 is pivotally connected to each lever 32 by means of pin 62 inserted through suitable apertures therefor in the dog 60 and the bifurcate extensions 56. As better shown in FIG. 1, the locking dogs 60, in the clamping and locking positions of the levers 32, are shaped and disposed such that their end portions 64 bridge the gaps between the chamfered hub edge 66 of the roll 26 and the juxtaposed surfaces of the end cap 34. In furtherance of this purpose the dogs 60 and particularly their end portion 64 are shaped in conformance with the application of the several forces as shown in FIG. 1. Thus, the end portions 64 are provided with inclined surfaces 68 for complementary engagement with the chamfered edge portion 69 or the roll or sleeve 26. In particular the inclined edges 68 of the dogs 60 cooperate with the chamfered and similarly inclined edge surface 69 of the sleeve or roll 26 to provide a camming or wedging action as the dogs 60 are forcefully inserted between the edge portion 66 of the roll 26 and the end cap 34. Such forceful insertion endows the locking forces exerted by the automatic clamping and locking arrangement with a preloading capability. The dogs 60 are further provided with lateral edges 70 for sliding and bearing engagement with the adjacent surfaces of the end cap When the dogs 60 are thus inserted between the roll edge 66 and the end cap 34 reactive forces (arrows P2 and P3) are developed at the roll edge 66 and at the dog pivot pins 62 as shown in FIG. 1. These forces are counterbalanced (arrow P2 P3) by a force exerted against the lateral edges 70 of the dogs 60. Desirably the center line of each dog pivot pin 62 is axially aligned with the center line of the associated lever pin 42, as denoted by reference line 72, such that the reactive forces (arrow P3) applied to the levers 32 pass precisely through their pivot points 74 such that no torque is applied to the levers 32, particularly in a direction that would tend to displace the clamping projections 54 from the adjacent surfaces of the sleeve or roll 26. Accordingly, the dogs 60 are capable of supplying large locking forces to the roll or sleeve 26 which are more than adequate to counterbalance the large axial thrusts that may be imparted to the roll 26, for example during operation of a leveler or straightener of which the roll 26 may be a component. At the same time, there is no interference between any reactive components of these locking forces with the extremely large clamping forces also developed by the levers 32.

It will be appreciated that the cap member 34 can be omitted and its function absorbed by terminating the chamber means 30 short of the adjacent or cantilevered end of the shaft 22. In effect, then, the end cap is an extension of the shaft 22, and the dogs are insert able between the adjacent end 66 of the sleeve or roll 26 and adjacent end surfaces of the chamber means 30. In the illustrated embodiment, of course, the chamber means 30 are delimited by the cap member 34. In either case, the sleeve or roll 26 is thus locked upon the shaft 22 against suitable stop means 71 disposed thereon at the other end of the roll or sleeve 26. The roll 26 is thus retained against severe thrust forces in either axial direction thereof.

With the arrangement just described it is readily apparent that the levers 32 of the automatic clamping and locking device 20 are self-energizable, by virtue of their springs 46 to apply automatically both extremely large clamping forces and extremely large locking forces to the sleeve or roll 26 to assure its retention and position upon the shaft 22.

With reference now to FIG. 2 of the drawings, means are provided for the quick-unclamping and the quickunlocking of the automatic clamping and locking arrangement 20. By operation of such means, the levers 32 are both pivoted simultaneously to their positions as shown in FIG. 2 whereat the clamping projections 54 are pivoted out of contact with the adjacent surfaces of the sleeve or roll 26. At the same time the locking dogs 60 are withdrawn from between the roll hub or edge portion 66 and the end cap 34 to their positions as shown in FIG. 2. At these positions of the locking dogs 60 and the clamping projections 54 it is readily appar ent that a used roll or sleeve such as the roll 26 can be readily and quickly withdrawn from the shaft 22. Likewise, a new or replacement roll (not shown) can be quickly and readily slipped over the shaft 22 and the clamping and locking arrangement 20, when the levers 32 thereof are in their positions as illustrated in FIG. 2. It will also be apparent that no removal of hardware from the roll 26 or shaft 22 is necessary.

One form of such actuating means includes stud member 76, which is shaped for insertion into and through the cylindrical recess 28 of the shaft 22. The recess 28 and the stud member 76 are considerably elongated for purposes mentioned hereinafter. For the bare actuation of the clamping and locking arrangement 20, the stud member 76 need be inserted only to the extent that its conical end portion 78 just passes the cam followers 50 of the levers 32 as denoted by chain outline 80 of the stud member. The conical end portion 78 acts, of course, as a camming surface for cooperative engagement with the cam followers 50 in order to pivot the levers 32 against the action of their springs 46 to the positions thereof as shown in FIG. 2. At this position, each lever and its associated components are sufficiently disengaged, as explained previously, that the roll or sleeve 26 can be withdrawn from the shaft 22.

Although a stud member of suitable length as men tioned previously can be inserted individually into each of the openings 82 (FIG. 3) of a number of roll shafts, such as used in conjunction with a roll leveler or straightener, suitable and unexpected means are provided by the invention for manipulating a number of the clamping and locking devices simultaneously in conjunction with the simultaneous removal of a number of rolls, such as the rolls 26 and 26, and simulta neous replacement thereof. This involves use of a roll changing apparatus, such as that disclosed in the aforementioned patent, which however is unexpectedly modified as illustrated in FIG. 2. A suitable form of the modified roll changing apparatus 82 comprises a supporting standard 84 on which frame 86, in this example, is rotatably mounted. The frame 86 can include a turntable 88 rotated by pinion 90 for rotation of the frame 86. The standard 84 can be mounted on a carriage or railway type car (not shown) for movement toward and away from a plurality of rolls such as the rolls 26 and 26 of FIG. 2. A suitable carriage for this purpose is disclosed in the aforementioned patent.

A plurality of roll sockets 92 and 94 are mounted on the frame 86. The sockets 92 and 94 can be arranged in two rows on one side of the frame 86 with the sockets 92, 94 representing one socket of each such row. As explained in the aforesaid patent, the rows of sockets are arranged in respective alignment with a similar configuration of rolls of a leveler or straightener, such as the straightener described and claimed in the aforesaid copending application. Similar rows of sockets 92, 94' can be arranged on the opposite side of the frame 86 for holding an array of replacement sleeves or rolls (not shown) for the aforementioned leveler or straightener, for example as taught in the aforementioned patent. In the illustrated arrangement, also each socket 92 or 94 is provided with suitable locking means such as levelers 96 operable through notches 98 in the sockets 92, 94 for engagement with flanged nut 100 threaded onto the roll or sleeve 26, for retaining the roll or sleeve 26 or 26 in the associated socket 92 or 94 of the roll changing apparatus 82.

As shown in FIG. 2 the roll changing apparatus 82 is particularly adapted for use with a plurality of rolls which are retained in position on their respective shafts by a like number of the automatic clamping and locking devices 20 disclosed herein. In the modified roll changing apparatus 86, a plurality of stud members, similar to the aforementioned stud member 76 are inserted respectively through the sockets 92, 94 and are secured as by welding or the like to plate 102 forming part of the frame structure 86 of the roll changing apparatus 82. When so mounted, the stud members 76 are located desirably within and preferably concentrically of their respective sockets 92, 94. On the reverse side of its frame structure 86, similar stud members such as the member 76 are similarly located on plate 102' within the sockets 92, 94.

In operation, the roll changing apparatus 82 is maneuvered into juxtaposition to a straightener or other apparatus having a plurality of rolls 26, 26' and associated supporting shafts 22. The changing apparatus 82 is then advanced toward the rolls 26, 26 and shafts 22 such that the stud members 76 are inserted simultaneously into holes 81 of the shafts 22 and end caps 34. When the stud members 76 are inserted to the positions denoted by chain-outline 80 thereofin FIG. 2, the automatic clamping and locking devices 20 are simultaneously inactivated as pointed out previously. The roll changing apparatus 82 is then moved closer to the rolls 26, 26 until their ring nuts 100 or other securance flanges are inserted into the corresponding sockets 92,

94 of the roll changing apparatus. The locking means 96 are then activated to clamp the rolls 26, 26 in position within the roll changing sockets 92, 94. The cylindrical recesses 28 are sufficiently elongated to permit the further insertion of the stud members 78 as the changing apparatus 82 is advanced such that the sockets 92, 94 engage the rolls 26, 26.

To withdraw the rolls 26, 26' the stud members 76 need only be of the length noted by chain-outline 80. However, to install new or replacement rolls the sockets 92', 94 of necessity are initially separated from the roll shafts 22 by the axial lengths of the new or replacement rolls, such as roll 26a. Hence, the stud members 76 are elongated to bridge such gap, as the automatic clamping and locking devices must be activated before the new rolls can engage the shafts 22 therefore.

In the particular form of the roll changing apparatus 82, replacement rolls (roll 26a) can be mounted in the sockets 92', 94 on the reverse side of the frame structure 86. After removal of the rolls 26, 26 the roll changing apparatus 82 can be withdrawn from the shafts 22, with the rolls 26, 26' then clamped on the roll changing apparatus 82. After the apparatus 82 is withdrawn sufficiently to clear the stud members 76, the turntable 88 and frame structure 86 can be rotated through one-half revolution whereupon the new or replacement rolls and the stud members 76 can then be presented to the shafts 22.

From the foregoing it will be apparent that novel and efficient forms of Automatic Clamping and Locking Apparatus have been described herein. While I have shown and described certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same it is to be distinctly understood that the invention is not limited thereto but may be' otherwise variously embodied and practiced within the spirit and scope of the invention.

I claim:

1. An automatic clamping arrangement for clamping a sleeve and the like onto a shaft and the like, said arrangement comprising at least two levers pivotally mounted on said shaft and disposed in chamber means therein, said levers being disposed for generally opposed movement toward and away from said sleeve when the latter is mounted upon said shaft, biasing means coupled to each of said levers for angularly displacing said levers about said pivot mountings such that a portion of each of said levers is advanced toward an adjacent surface of said sleeve, and a clamping projection on each of said lever portions disposed for bearing contact with said sleeve surfaces upon pivoting of said levers by said biasing means, said chamber means communicating through recess means opening onto a surface of said shaft for insertion of a tool generally between opposed second portions of said levers to pivot said levers in an opposite direction against the action of said biasing means to withdraw said clamping projections from said sleeve surfaces.

2. The combination according to claim I wherein said second lever portions are provided with cam follower means for cooperative engagement with a camming surface of said tool.

3. The combination according to claim 1 wherein said biasing means include a compressed spring for each of said levers, said springs being confined respec tively between retaining recesses on said levers and on spring retaining members mounted within said chamber means.

4. The combination according to claim 1 wherein said clamping projections are shaped to provide initially an edged contact with said adjacent surfaces respectively.

5. The combination according to claim 4 wherein said clamping projections are further shaped for sub stantially flush engagement with said sleeve surfaces at the fully pivoted positions of said levers by said biasing means. i

6. The combination according to claim 1 wherein said sleeve and said chamber means are disposed on an end portion of said shaft, the adjacent end of said shaft and said chamber means extend outwardly of said sleeve, an end cap ofa size such that said sleeve can be slipped thereover is secured an end portion of said shaft to define the adjacent ends of said chamber means, said end cap being thereby spaced from the adjacent end of said sleeve, and each of said levers having third portions disposed for insertion between said sleeve and said end cap upon pivoting of said levers under impetus of said biasing means.

7. The combination according to claim 1 wherein said chamber means terminate in said shaft outwardly of an adjacent end portion of said sleeve, and said levers each include third portions insertable between said sleeve end portion and adjacent end surfaces of said chamber means upon pivoting of said levers by said hiasing means to lock said sleeve on said shaft against stop means thereon disposed adjacent the other end of said sleeve. I

8. The combination according to claim 7 wherein said third lever portions include a like number of dogs pivotally mounted on said levers respectively and shaped for bearing insertion between said sleeve end and said chamber end surfaces.

9. The combination according to claim 8 wherein a pivot point of each of said dogs is axially aligned with a pivot point of the associated lever in avoidance of imposition of torque upon said lever by locking forces reactively imposed upon said dogs.

10. The combination according to claim 8 wherein said dogs and the adjacent edge of said sleeve are provided with camming or wedging surfaces for enlargement of the locking forces exerted by said dogs and said levers.

11. The combination according to claim 8 wherein each of said dogs is pivotally mounted between bifurcate extensions formed on said third portion of the associated lever.

12. The combination according to claim 1 wherein sleeve changing apparatus is provided for said sleeve and said shaft, said sleeve is cantilevered on said shaft and said recess means open onto an end of said shaft, said tool being an elongated stud member secured to said apparatus, said apparatus having at least one sleeve-receiving socket, said stud member being secured to said apparatus and protruding outwardly and centrally from said socket for insertion into said shaft recess and chamber means, and cooperating locking means are formed on said sleeve and on said socket for locking said sleeve to said socket during withdrawal and replacement movements thereof relative to said shaft.

13. The combination according to claim 12 including an additional socket for said sleeve located on said changing apparatus, said additional socket being similarly structured for retention of a replacement roll thereon, an additional stud member secured to said apparatus and likewise extending upwardly and centrally from said socket, and means for manipulating said apparatus for presenting either said first mentioned socket and stud member or said additional socket and stud member to said sleeve and said shaft,'said additional stud member being of sufficient length to bridge the gap necessitated by said replacement roll while engaging said levers.

14. Roll changing apparatus for use with a shaft having a cantilevered roll thereon and clamping mechanism therein for said roll, said clamping mechanism being actuatable by a tool insertable into axial recess means in said shaft, said recess means opening onto an end of said shaft, said changing apparatus having at least one sleeve-receiving socket, said tool being an elongated stud member secured to said changing apparatus and protruding outwardly from the interior of said socket for insertion into said shaft recess means, and cooperating locking means formed on said roll and on said socket for locking said roll to said socket during withdrawal and replacement movements thereof rela tive to said shaft.

15. The combination according to claim 14 wherein said stud member has a camming surface on its outer end portion disposed for cooperation with cam follower means forming part of said clamping mechanism. 

1. An automatic clamping arrangement for clamping a sleeve and the like onto a shaft and the like, said arrangEment comprising at least two levers pivotally mounted on said shaft and disposed in chamber means therein, said levers being disposed for generally opposed movement toward and away from said sleeve when the latter is mounted upon said shaft, biasing means coupled to each of said levers for angularly displacing said levers about said pivot mountings such that a portion of each of said levers is advanced toward an adjacent surface of said sleeve, and a clamping projection on each of said lever portions disposed for bearing contact with said sleeve surfaces upon pivoting of said levers by said biasing means, said chamber means communicating through recess means opening onto a surface of said shaft for insertion of a tool generally between opposed second portions of said levers to pivot said levers in an opposite direction against the action of said biasing means to withdraw said clamping projections from said sleeve surfaces.
 2. The combination according to claim 1 wherein said second lever portions are provided with cam follower means for cooperative engagement with a camming surface of said tool.
 3. The combination according to claim 1 wherein said biasing means include a compressed spring for each of said levers, said springs being confined respectively between retaining recesses on said levers and on spring retaining members mounted within said chamber means.
 4. The combination according to claim 1 wherein said clamping projections are shaped to provide initially an edged contact with said adjacent surfaces respectively.
 5. The combination according to claim 4 wherein said clamping projections are further shaped for substantially flush engagement with said sleeve surfaces at the fully pivoted positions of said levers by said biasing means.
 6. The combination according to claim 1 wherein said sleeve and said chamber means are disposed on an end portion of said shaft, the adjacent end of said shaft and said chamber means extend outwardly of said sleeve, an end cap of a size such that said sleeve can be slipped thereover is secured an end portion of said shaft to define the adjacent ends of said chamber means, said end cap being thereby spaced from the adjacent end of said sleeve, and each of said levers having third portions disposed for insertion between said sleeve and said end cap upon pivoting of said levers under impetus of said biasing means.
 7. The combination according to claim 1 wherein said chamber means terminate in said shaft outwardly of an adjacent end portion of said sleeve, and said levers each include third portions insertable between said sleeve end portion and adjacent end surfaces of said chamber means upon pivoting of said levers by said biasing means to lock said sleeve on said shaft against stop means thereon disposed adjacent the other end of said sleeve.
 8. The combination according to claim 7 wherein said third lever portions include a like number of dogs pivotally mounted on said levers respectively and shaped for bearing insertion between said sleeve end and said chamber end surfaces.
 9. The combination according to claim 8 wherein a pivot point of each of said dogs is axially aligned with a pivot point of the associated lever in avoidance of imposition of torque upon said lever by locking forces reactively imposed upon said dogs.
 10. The combination according to claim 8 wherein said dogs and the adjacent edge of said sleeve are provided with camming or wedging surfaces for enlargement of the locking forces exerted by said dogs and said levers.
 11. The combination according to claim 8 wherein each of said dogs is pivotally mounted between bifurcate extensions formed on said third portion of the associated lever.
 12. The combination according to claim 1 wherein sleeve changing apparatus is provided for said sleeve and said shaft, said sleeve is cantilevered on said shaft and said recess means open onto an end of said shaft, said tool being an elongated stud member secured to said apparatus, said apparatus having at least oNe sleeve-receiving socket, said stud member being secured to said apparatus and protruding outwardly and centrally from said socket for insertion into said shaft recess and chamber means, and cooperating locking means are formed on said sleeve and on said socket for locking said sleeve to said socket during withdrawal and replacement movements thereof relative to said shaft.
 13. The combination according to claim 12 including an additional socket for said sleeve located on said changing apparatus, said additional socket being similarly structured for retention of a replacement roll thereon, an additional stud member secured to said apparatus and likewise extending upwardly and centrally from said socket, and means for manipulating said apparatus for presenting either said first mentioned socket and stud member or said additional socket and stud member to said sleeve and said shaft, said additional stud member being of sufficient length to bridge the gap necessitated by said replacement roll while engaging said levers.
 14. Roll changing apparatus for use with a shaft having a cantilevered roll thereon and clamping mechanism therein for said roll, said clamping mechanism being actuatable by a tool insertable into axial recess means in said shaft, said recess means opening onto an end of said shaft, said changing apparatus having at least one sleeve-receiving socket, said tool being an elongated stud member secured to said changing apparatus and protruding outwardly from the interior of said socket for insertion into said shaft recess means, and cooperating locking means formed on said roll and on said socket for locking said roll to said socket during withdrawal and replacement movements thereof relative to said shaft.
 15. The combination according to claim 14 wherein said stud member has a camming surface on its outer end portion disposed for cooperation with cam follower means forming part of said clamping mechanism. 